The present invention relates to a method for determining a cause of a voltage outage load side from a circuit breaker by means of an auxiliary unit, through the absence of voltage downstream from the circuit breaker corresponding to an opening of the circuit breaker or to a drop in voltage at the input of the circuit breaker below a first reference voltage value.
The present invention also relates to an auxiliary unit for an electric circuit breaker, the circuit breaker being, in an open position, capable of interrupting the flow of an electric current in an electric connection comprising at least one electric conductor.
The present invention also relates to an electric system comprising an electric circuit breaker and such an auxiliary unit coupled with the electric circuit breaker.
A persisting challenge in the field of circuit breakers is to identify, following the opening of the circuit breaker, the type of fault having caused this opening.
The use of an auxiliary signalling module for a circuit breaker comprising a first switch indicating the closed or open state of the contacts of the circuit breaker and a second switch indicating the armed or triggered state of the circuit breaker is thus known from EP-A1-1065691. Thus, once the auxiliary module is coupled with the circuit breaker, the switches are able to interfere with the mechanism of the circuit breaker and to be moved depending on the state of the circuit breaker. Such an auxiliary module therefore gives the possibility of knowing whether the circuit breaker is open following manual actuation of the opening of the circuit breaker, the state of the circuit breaker then also being called an open state, or else following the presence of a fault, such as an electric overload on the electric connection, having caused the triggering of the circuit breaker, the state of the circuit breaker also being called a triggered-on-fault state. When the circuit breaker is in the closed position, the state of the circuit breaker is also called a closed state.
However, such an auxiliary module for a circuit breaker gives the possibility of only knowing the state of the circuit breaker from among the open, closed or triggered-on-fault states and does not give the possibility of specifically knowing a cause of the triggering of the electric circuit breaker, i.e. a cause of the triggered state of the circuit breaker.